As a Brit and mentor, but not a teacher, I would interpret your sentences as follows:
1. The referee has to think (How?) [in] the [same] way [that] the players do/think.
2. I'm trying to think (what?) positive thoughts.
They both relate, really, to "directing one's mind towards someone or something", reflecting definition 2a, below, in the OED definition of "think":
1 have a particular opinion, belief, or idea about someone or something.
2 a) direct one’s mind towards someone or something;
b) use one’s mind actively to form connected ideas.
3 (think of/about) take into account or consideration.
4 (think of/about) consider the possibility or advantages of.
5 (think of) have a particular opinion of.
6 call something to mind; remember.
Does this help your understanding?